blocks|key|3187133|text|试一试|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3187134|-(void)displayData{
++++NSMutableString+*outputString+=+[NSMutableString+string];
++++for+(NSDictionary+*dict+in+_myArray)+{
++++++++[outputString+stringByAppendingFormat:@"%25@\n",dict[@"Date"]];
++++}

++++_myTextView.text+=+[NSString+stringWithString:outputString];
}|code-block|syntax|javascript|3187135|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Try

<pre><code>-(void)displayData{
 NSMutableString *outputString = [NSMutableString string];
 for (NSDictionary *dict in _myArray) {
 [outputString stringByAppendingFormat:@"%@\n",dict[@"Date"]];
 }

 _myTextView.text = [NSString stringWithString:outputString];
}
</code></pre>

blocks|key|1357005|text|for(int+i+=0+;i+<[array+count];i%2B%2B)
{
++NSLog(@"%25@",[[array+objectAtIndex:i]allKeys]);
+}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1357006|此方法将打印所有密钥|unstyled|1357007|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>for(int i =0 ;i &lt;[array count];i++)
{
 NSLog(@"%@",[[array objectAtIndex:i]allKeys]);
 }
</code></pre>

this method will print all the keys

blocks|key|3187170|text|第一件事是每次向数组添加新对象时都必须分配一个新字典，否则字典将只保存最后一个值，因此|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3187171|+-+(IBAction)addData:(id)sender+
+{

+++NSMutableDictionary+*_myDictionary=[[NSMutableDictionary+alloc]+init];

+++[_myDictionary+setObject:_dateLabel.text+forKey:dateString];
+++[_myDictionary+setObject:_nNumber.text+forKey:timeString];
+++[_myDictionary+setObject:_type.text+forKey:typeString];

+++[_myArray+addObject:_myDictionary];

+++[self+display]
}|code-block|syntax|javascript|3187172|现在，so所在的部分正在显示值|3187173|-(void)displayData
{
+++for+(int+i+=+0;+i<_myArray.count;+i%2B%2B)+
++{
++++++NSMutableDictionary+*dictionary+=+[_myArray+objectAtIndexPath:i];

++++++outputString+=+[outputString+stringByAppendingFormat:@"%25@\n",[dictionary+objectForKey:@"Date"]];

+++}
+++_myTextView.text+=+[NSString+stringWithFormat:@"%25@",outputString];+

}|3187174|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

First thing is that you have to allocate a new dictionary everytime you are adding new object to the array , otherwise your dictionary will only be holding the last value so 

<pre><code> - (IBAction)addData:(id)sender 
 {

 NSMutableDictionary *_myDictionary=[[NSMutableDictionary alloc] init];

 [_myDictionary setObject:_dateLabel.text forKey:dateString];
 [_myDictionary setObject:_nNumber.text forKey:timeString];
 [_myDictionary setObject:_type.text forKey:typeString];

 [_myArray addObject:_myDictionary];

 [self display]
}
</code></pre>

Now the part where so are displaying the value

<pre><code>-(void)displayData
{
 for (int i = 0; i&lt;_myArray.count; i++) 
 {
 NSMutableDictionary *dictionary = [_myArray objectAtIndexPath:i];

 outputString = [outputString stringByAppendingFormat:@"%@\n",[dictionary objectForKey:@"Date"]];

 }
 _myTextView.text = [NSString stringWithFormat:@"%@",outputString]; 

}
</code></pre>

blocks|key|1357055|text|您混淆了实例变量和局部变量，并且没有在循环中正确更新。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1357056|理想情况下：|1357057|1357058|myArray将是一个实例变量(就像你拥有它一样，在你需要的每个方法中，它都将是一个局部变量。|ordered-list-item|1357059|1357060|这是持久化数据和工作数据的区别。|1357061|试着这样做：|1357062|NSString+*dateString+=+@"Date";
NSString+*timeString+=+@"Time";
NSString+*typeString+=+@"Type";

-+(IBAction)addData:(id)sender+{

++++NSMutableDictionary+*dict+=+[NSMutableDictionary+dictionary];

++++[dict+setObject:_dateLabel.text+forKey:dateString];
++++[dict+setObject:_nNumber.text+forKey:timeString];
++++[dict+setObject:_type.text+forKey:typeString];

++++[_myArray+addObject:dict];

++++[self+display]
}


-(void)displayData{

++++NSString+*outputString+=+@"";

++++for+(int+i+=+0;+i<_myArray.count;+i%2B%2B)+{
++++++++NSDictionary+*dict+=+[_myArray+objectAtIndex:i];
++++++++outputString+=+[outputString+stringByAppendingFormat:@"%25@\n",[dict+objectForKey:@"Date"]];
++++}

++++_myTextView.text+=+outputString;
}|code-block|syntax|javascript|1357063|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|U|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|V|8|@]|9|@]|A|$]]|$1|E|3|F|5|G|7|W|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|X|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|Y|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|Z|8|@]|9|@]|A|$]]|$1|M|3|N|5|O|7|10|8|@]|9|@]|A|$P|Q]]|$1|R|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|S|$]]

You're mixing up instance and local variables, and not updating in the loop properly.

Ideally:

<ol>
<li>myArray will be an instance variable (like you have it now).</li>
<li>myDictionary will be a local variable in each method you need it.</li>
</ol>

This differentiates between your persistent data and your working data.

Try this instead:

<pre><code>NSString *dateString = @"Date";
NSString *timeString = @"Time";
NSString *typeString = @"Type";

- (IBAction)addData:(id)sender {

 NSMutableDictionary *dict = [NSMutableDictionary dictionary];

 [dict setObject:_dateLabel.text forKey:dateString];
 [dict setObject:_nNumber.text forKey:timeString];
 [dict setObject:_type.text forKey:typeString];

 [_myArray addObject:dict];

 [self display]
}


-(void)displayData{

 NSString *outputString = @"";

 for (int i = 0; i&lt;_myArray.count; i++) {
 NSDictionary *dict = [_myArray objectAtIndex:i];
 outputString = [outputString stringByAppendingFormat:@"%@\n",[dict objectForKey:@"Date"]];
 }

 _myTextView.text = outputString;
}
</code></pre>

I have an array that holds several <code>NSMutableDictionary</code> objects.

Each time text fields are filled out and the submit button is pressed:

<pre><code>//The strings
NSString *dateString = @"Date";
NSString *timeString = @"Time";
NSString *typeString = @"Type";

- (IBAction)addData:(id)sender {

[_myDictionary setObject:_dateLabel.text forKey:dateString];
[_myDictionary setObject:_nNumber.text forKey:timeString];
[_myDictionary setObject:_type.text forKey:typeString];

[_myArray addObject:_myDictionary];

[self display]
}
</code></pre>

Then I am trying to display the results in a UItextView (in this example the date) but I don't know how.

<pre><code> -(void)displayData{

 for (int i = 0; i&lt;_myArray.count; i++) {
 [_myArray objectAtIndex:i];
 outputString = [outputString stringByAppendingFormat:@"%@\n",[_myDictionary objectForKey:@"Date"]];

 }
 _myTextView.text = [NSString stringWithFormat:@"%@",outputString];

}
</code></pre>

This ends up displaying the date for the last Dictionary in the array. I can't even figure out how to log the date from a specific dictionary. 
Say <code>[_myArray objectAtIndex:3] [_myDictionary objectForKey:@"Date"]</code>. How would I log the date from the 3rd index?

Hope this makes sense

<pre><code>EDIT SOLUTION

for (int i = 0; i&lt;_myArray.count; i++)
 {

 outputString = [outputString stringByAppendingFormat:@"%@ %@\n",[[_myArray objectAtIndex:i]objectForKey:@"Date"], [[_myArray objectAtIndex:i]objectForKey:@"Time"]];

 }
 _myTextView.text = [NSString stringWithFormat:@"%@",outputString];

}
</code></pre>

Thanks for all the quick help!!

Find Dictionary Key inside and Array of Dictionaries

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有一个包含几个NSMutableDictionary对象的数组。每次填写文本字段并按下提交按钮时：//The stringsNSString *dateString = @"Date";NSString *timeString = @"Time";NSString *typeString = @"Type";- (I...

问在字典内部和字典数组中查找字典键
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问在字典内部和字典数组中查找字典键EN